Wow. That's quite a write up, E-ko. You should (if you haven't already) write that up as a guide.

When I do rotoscoping of characters into other series and such (WLtFO, Samurai Windu) I tend to do it entirely in After Effects using its internal masking capabilities. This has both its advantages and its disadvantages. Disclaimer: I'm writing this up from memory, I don't have a computer with AE in front of me, so hopefully I won't screw things up too badly. Also note the keys I talk about are the PC shortcut keys... I imagine they're similiar on a Mac, but I don't know for sure ... I'd also advise reading through all of this before trying it...

So yeah... I think you have an older version of After Effects? I've been trying to step through this and you lose me at about "changing the color of the mask". >>; What you say should be there (the menu for changing the colors) simply isn't. I'm running After Effects 6.5.1 Pro... is your version different? If so, do you know how to continue on after you've made the mask in 6.5.1 pro?

Don't eat me, please help me. You have to understand that this masking stuff is going to doom my AMV to be unless I get it to work.

I need to mask out the background of a certain scene so that only the character is "visible." Simple, huh? He will be placed against a new background, eventually. I slapped a mask on him in AE, but it took forever using that dratted pen tool, so I figured I'd export the frame to PS, create a mask a la alpha channel goodness, and import it back into AE.

Maybe this is where I'm going wrong. Maybe I can't do this at all (the alpha channel masking in PS for use in AE). Maybe I need to export every frame to PS, cut out what I don't want, and import it. But this just doesn't seem logical. If I've got to mask out the background of a static character whose eyes/mouth is moving, this just won't work and this is what masks are designed to handle.

The problem is that I cannot create an alpha channel mask in PS. I cannot get my alpha channels to stick. No, not even stick, apply themselves! What's worse, it used to work for me. Once upon a time, using E-ko's method, I actually created an alpha channel mask that worked like it was supposed to in Premier. Now, suddenly, for no apparent reason, It. Does. Not. Work. For. Me. I've referred to other, quite similar methods for mask creation, and THEY do not work for me.

I think something's bonkers with my PS program. Up until the point at which I hit "apply layer mask" everything looks decent (alpha channel exists, with correct transparency). However, applying the mask to my target layer deletes the entire contents of that layer, and of course takes my carefully constructed alpha channel mask with it! PS never did this to me before...

Maybe my ideas about alpha channel masks are messed up...maybe that's the problem. Maybe what I thought I did when it *worked* was something else completely? I have no idea. But I'd love to figure out what's wrong.

p.s. I can cheat a little using alternative blending modes in Premiere/AE for B&W images used as masks, but it's not ideal. I also can cheat a bit using track mattes, but again, it's not ideal. Alpha masks are such a simple thing to create, and yet I can't seem to do it. Any advice (including reinstalling my PS program, which is what will happen if it doesn't start cooperating) is much appreciated!

DriftRoot wrote:Mmm, yes, but I was trying to get out of using paths unless I absolutely have to, it would be nice to have an alpha channel mask work. Hehe, are you saying I have to?

Well, you could make an alpha channel mask <i>with</i> paths... I don't think I've ever tried doing it any other way (with the possible exception of the Polygonal Lasso, which I do not recommend), so I don't know what other techniques people have for it.

ShadowNOS wrote:Ok I have one small question I knwo I could go through those tuts but simply all I need to know is when your done with it what do you save it as to get it to be transparent.

I keep saving it and importing it into premiere elements and it still has a background. I mean the real one is gone but the black one is still there.

You could try saving as a sequence of TIFF images with transparencies (or even GIFs), or as a video with a codec that supports RGB32 (RGBA, or RGB with an alpha channel)...

DriftRoot wrote:Mmm, yes, but I was trying to get out of using paths unless I absolutely have to, it would be nice to have an alpha channel mask work. Hehe, are you saying I have to?

Well, you could make an alpha channel mask <i>with</i> paths... I don't think I've ever tried doing it any other way (with the possible exception of the Polygonal Lasso, which I do not recommend), so I don't know what other techniques people have for it.

ShadowNOS wrote:Ok I have one small question I knwo I could go through those tuts but simply all I need to know is when your done with it what do you save it as to get it to be transparent.

I keep saving it and importing it into premiere elements and it still has a background. I mean the real one is gone but the black one is still there.

You could try saving as a sequence of TIFF images with transparencies (or even GIFs), or as a video with a codec that supports RGB32 (RGBA, or RGB with an alpha channel)...

I'm just cutting out what I dont need in AE and then exporting it as a png then I move on to the next frame and do the same. So I use my orignal as a guide and just place the png files in the correct order. It may seem hard or whatnot but for now its the easiet thing and its coming along really really good.

Scintilla wrote:Well, you could make an alpha channel mask <i>with</i> paths... I don't think I've ever tried doing it any other way (with the possible exception of the Polygonal Lasso, which I do not recommend), so I don't know what other techniques people have for it.

A mask with paths results in the same effect as a mask without paths, though (I'd think), if everything works the way it's supposed to. That also assumes my alpha channels work...which they don't. Not in PS, not in Premier, not in AE. Again, I can't get them to stick via the masky method. Track m's work in some instances when I use an image file as the mask, but I don't want to work with things UNDER things, I want things OVER things. Same goes for the multiply tactic. *sobs* Ok, that was too melodramatic.

I may have to harass my poor, unsuspecting CS2 instructors about this issue:
"Can you explain how to utilize alpha channels across programs?" [mind, no one else in the class may know what a channel is, nevermind an alpha type]
"Why do you want to know?"
"Oh, well, I'm trying to do something with...something and I can't get it to work."
"Can you show me?"
"No."

For the record only: There WAS something wrong with my Photoshop software, it really was not processing alpha channels correctly, among other things I've noticed since upgrading to a newer version (7.0 to CS2). Even reinstalling PS didn't solve the problem, so the program was definately messed up at some level.

Mask maker wanna-be's: The method outlined in this thread SHOULD work - if it doesn't and you're really, truly following the guide to the letter, then something else is wrong.

Thanks to everyone who tried to help. Now you know why none of it did help.

Well, faulty software is the least of my worries. I'm sure this is plain stupid, but my masks in AE only have four edges that I can move. So I can only select rectangles, trapeziums and the like with masks. How do I add dots to the goddamned thing?

Please give answers in the most simplistic, step-by-step and overall moronic way. It's my first shot at AE and the whole interface still makes me dizzy (not to mention my <10second limit for RAM previews).

Thanks in advance

-gepetto

And God spoke unto the Chicken, and He said: "Thou shalt crosseth the road", and the Chicken did cross the road, and there was much rejoicing.My DeviantART profile

If you're having trouble creating masks in AE and find the interface extremely daunting, the easiest way to fix this problem is not to create them in AE. The program has many functions that allow for details, non-geometric masks, but it may be less of a headache to not bother with them right now.

Use a good image editing program to create the kind of mask you want, make sure the resulting image has opacity values, and import THAT into AE to use as your mask.